Safe Haskell	Trustworthy
Language	Haskell2010

Control.Monad.STE

Synopsis

Documentation

data STE e s a Source

Instances

Monad (STE e s) Source
Functor (STE e s) Source
MonadFix (STE e s) Source
Applicative (STE e s) Source
(~) * SomeException err => MonadThrow (STE err s) Source
PrimMonad (STE e s) Source
PrimBase (STE e s) Source
type PrimState (STE e s) = s Source

runSTE :: (forall s. STE e s a) -> (Either e a -> b) -> b Source

runSTE is the workhorse of the STE monad. Runs an STE computation, and also does the toplevel handling of the abortive throwSTE operator. The naive way to handle errors is to simply write handleSTE id md. runSTE does not and cannot (by design) handle pure or async exceptions.

throwSTE :: forall e s a. e -> STE e s a Source

throwSTE is the STE sibling of throwIO, and its argument must match the e parameter in STE e s a. There is also no Exception e constraint. throwSTE should be thought of as an "abort" operation which is guaranteed to be caught/handled by runSTE.

handleSTE :: (Either e a -> b) -> (forall s. STE e s a) -> b Source

handleSTE is a flipped convenience function version of runSTE